Highly sensitive photoalignment of liquid crystals (LCs) can be realized by the polarization preserved triplet energy transfer from doped sensitizers to cinnamate side chains of a photocrosslinkable polymer. Linearly polarized irradiation of sensitizer-doped polymer films with 365nm light for selective excitation of the triplet photosensitizer gives rise to azimuthal photodichroism of cinnamates as a result of nanometric triplet energy transfer process preserving the polarization state of triplet-excited photosensitizer. This phenomenon is applicable to the surface-assisted orientational photocontrol of nematic LCs with high performance of extremely low exposure energies.

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